/*
 * ------------------------------------------------------------------------
 *  Copyright by KNIME AG, Zurich, Switzerland
 *  Website: http://www.knime.com; Email: contact@knime.com
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License, Version 3, as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses>.
 *
 *  Additional permission under GNU GPL version 3 section 7:
 *
 *  KNIME interoperates with ECLIPSE solely via ECLIPSE's plug-in APIs.
 *  Hence, KNIME and ECLIPSE are both independent programs and are not
 *  derived from each other. Should, however, the interpretation of the
 *  GNU GPL Version 3 ("License") under any applicable laws result in
 *  KNIME and ECLIPSE being a combined program, KNIME AG herewith grants
 *  you the additional permission to use and propagate KNIME together with
 *  ECLIPSE with only the license terms in place for ECLIPSE applying to
 *  ECLIPSE and the GNU GPL Version 3 applying for KNIME, provided the
 *  license terms of ECLIPSE themselves allow for the respective use and
 *  propagation of ECLIPSE together with KNIME.
 *
 *  Additional permission relating to nodes for KNIME that extend the Node
 *  Extension (and in particular that are based on subclasses of NodeModel,
 *  NodeDialog, and NodeView) and that only interoperate with KNIME through
 *  standard APIs ("Nodes"):
 *  Nodes are deemed to be separate and independent programs and to not be
 *  covered works.  Notwithstanding anything to the contrary in the
 *  License, the License does not apply to Nodes, you are not required to
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 *  prepare and propagate Nodes, in each case even if such Nodes are
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 *  may freely choose the license terms applicable to such Node, including
 *  when such Node is propagated with or for interoperation with KNIME.
 * ---------------------------------------------------------------------
 *
 * History
 *   Aug 11, 2008 (wiswedel): created
 */
package org.knime.core.data.collection;

import java.util.Iterator;

import org.knime.core.data.DataCell;

/**
 * Iterator on a collection of {@link DataCell} objects, permitting
 * the access on underlying
 * {@link org.knime.core.data.container.BlobWrapperDataCell BlobWrapperDataCell}
 * if applicable.
 *
 * <p>
 * Instances of this iterator are returned by the
 * {@link CollectionDataValue#iterator()} method when the collection contains
 * wrapped blobs. The framework will handle such cases with care, that is,
 * by accessing the wrapper cell, not the actual blob (which might be
 * unnecessary and expensive).
 * @author Bernd Wiswedel, University of Konstanz
 */
public interface BlobSupportDataCellIterator extends Iterator<DataCell> {

    /** Get the next DataCell, not unwrapping the blob when it is a
     * {@link org.knime.core.data.container.BlobWrapperDataCell
     * BlobWrapperDataCell}.
     * @return The next cell.
     */
    public DataCell nextWithBlobSupport();

    /** Replaces the last returned element with a wrapper cell that contains additional information. Necessary when
     * a blob gets copied because it belongs to a non global table (created in a table that is not (yet) part of the
     * output port).
     * @param cell ...
     * @since 2.7
     */
    // method added in 2.7 ... assuming that no one is implementing this interface but using
    // DefaultBlobSupportDataCellIterator instead.
    public void replaceLastReturnedWithWrapperCell(final DataCell cell);

}
